In elevators, the ropes connected to the elevator car are generally guided by rope wheels. The ropes pass around the rope wheel bending against the rim thereof. During car travel, the ropes connected to the car continuously run around the rope wheel. Any section of the rope that runs over the rope wheel undergoes a bending cycle, which involves bending into a curved shape and a a subsequent straightening. The ropes normally endure without breaking several hundred thousand bending-cycles. However, the ropes are not allowed to be used until they break. The ropes need to be monitored, maintained and replaced with new ones early before breaking so as to avoid hazardous situations. The need for maintenance or replacement of ropes has been determined either by visual inspection or by complicated algorithms associating rope sections and determining bends undergone by each point of rope. One method according to prior art is disclosed in a European patent document EP2303749B1. Generally, visual inspection is troublesome and inaccurate way of monitoring the condition of the ropes. The use of complicated algorithms, on the other hand, leads to complicated programs, and their implementation is likely to require additional processor capacity for the elevator. Furthermore, algorithms according to the prior art, have necessitated a very specific association process of associating each of plural specific rope sections to one bending counter counting bendings of that specific rope section. This association process, as well as the overall method has been complicated and difficult to perform, and it produces information which is complicated to evaluate. It has come up a need for an efficient and simple, yet reasonably reliable way of determining rope condition.